2012 Sportsman 400/500 and EFI Tractor Service Manual 9923412, Page 132Get this manual
CARBURATION AND FUEL SYSTEM FUEL PUMP (CARBURATED)
This ATV is equipped with pressure regulated fuel pump (1-3 PSI)The pump is located under the left front fender of the machineTo test the fuel pump: 1Turn fuel off2Disconnect impulse line from pump3Connect Mity-VacTM(PN 2870975) to the impulse line fitting on the pump
FUEL GAUGE SENDING UNIT TEST
Fuel Sending Unit Test
If the fuel gauge reading on the instrument cluster is not working, or if the display reading differs in large comparison to the fuel in the tank, perform resistance test on the fuel sender1Open the front rack storage area2Remove the (4) T-25 screws securing the access cover to the front cab as shown belowImpulse Hose
4Apply inches (Hg) vacuum to the pump fittingThe diaphragm should hold vacuum indefinitelyIf fuel is present in the impulse line or vacuum chamber of the pump, the diaphragm is rupturedThe pump must be replaced